We know she's battling brain cancer, but you may not know she's also been struggling with chronic knee pain for years. As a contestant on season 17 of "Dancing With the Stars," Harper practices around the clock.
"I'm 74, the knees are there for 74, and they are not used this 4, 5,6 hours a day rehearsal," said Harper.
Harper says she's already had a partial knee replacement in that knee, but the wear and tear is taking its toll.
"These last two weeks, I guess I was stomping, doing the Paso Doble and being Spanish, and it just started to hurt," said Harper.
An MRI at the DISC Sports & Spine Center revealed not only osteoarthritis, but that Harper has a meniscus tear. An injury to the rubbery disc that cushions your knee is common, but it gets easier to tear as you age.
"Valerie's dancing five hours a day, the day before, the day of, the day after, every day, so we can't cause undue fatigue," said Dr. Joseph Horrigan, a chiropractor who specializes in treating athletic injuries.
Horrigan says many times small meniscus tears aren't the source of pain, so he concentrates his therapy on the rest of the leg.
"Keeping a joint mobile is very important and there are many ways to keep a joint mobile," he said.
The technique is called soft tissue mobilization. The goal is to lengthen tight muscles, break up stiff or scarred tissue and reduce inflammation.
"What has to be applied as needed to the particular patient once she's out of this competition, then we can let the tissues heal and calm down," said Horrigan.
Harper's fans keep her going.
"I really feel connected to those people throwing out all that love," Harper said.
And when you're faced with terminal brain cancer, Harper says you learn to keep things in perspective.
"One day at a time -- just like anyone else with problems," said Harper.
Harper says her brain scans show that the cancer is not progressing but she doesn't take anything for granted.
The treatment she receives for her knee, called soft tissue mobilization, is often covered by insurance. But the cost without insurance is about $150, and on average, it takes about six to eight treatments.